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The pulsed laser deposition of large area Y-Ba-Cu-O thin films is described, and the effects of laser spot dimension, laser fluence and target topography on plasma plume distribution, is investigated.

Laser deposition methods of large area thin films are reported and obtained films were tested and optical density measured.

Using modeling and computer simulation techniques, we conducted a comprehensive analysis of heat propagation processes and noise determination in a nanoscale three-layer detection pixel of a thermoelectric single-photon detector. The detection pixel comprises an absorber, a thermoelectric sensor, and a heat sink stacked on top of each other on a dielectric substrate. Our research was aimed at studying the spread of heat inside the detection pixel following the absorption of single photons with energies ranging from 0.8 to 7.1 eV (1550–175 nm) in tungsten or molybdenum absorbers of various thicknesses. The simulation was executed based on the equation for heat propagation within a limited volume. We explored temporal temperature variations in different regions of the detection pixel and analyzed the average temperature gradient across the sensor and heat sink surfaces. Parameters such as signal power resulting from the photon absorption, equivalent noise power, and signal-to-noise ratio were determined. Our results indicate that detection pixels consisting of W or Mo absorbers, a thermoelectric sensor La0.99Ce0.01B6 , and a Mo heat sink, with a 15 nm thick absorber and a surface area of 1 μm2 , can effectively detect single photons across a broad spectrum from far ultraviolet to near infrared. The calculated signal-to-noise ratios and temporal characteristics indicate the possibility of using this thermoelectric detection pixel design in optical microchips and large-scale multi-pixel cameras. [ABSTRACT FROM AUTHOR]

We present the results of modeling and simulation of heat propagation processes taking place in SiO2/W/CeB6/W four-layer detection pixel of a thermoelectric single-photon detector after simultaneous absorption of two, three, and four photons with energy 0.8 eV at different distances from each other as well as many photons absorption at different optical delay. Calculations were carried out based on the equation of heat propagation from a limited volume using the three-dimensional matrix method for differential equations. We have shown that a thermoelectric detector is able to count the number of absorbed photons. Detection pixels of usable size and high detection efficiency are found to have a count rate up to 1014 cps. [ABSTRACT FROM AUTHOR]

In this paper we have proposed the design of a single-photon thermoelectric detector’s detection pixel consisting of heat sink (W), thermoelectric sensor (CeB6), absorber (W), and antireflection layer (SiO2). It is justified that the detector with such a detection pixel can provide for the system efficiency above 90% for photons with energy 0.8–4 eV. Modeling and simulation are used to study the processes of heat propagation in four-layer detection pixel of a thermoelectric single-photon detector after photon absorption. Calculations were carried out on the basis of the equation of heat distribution from a limited volume using the three-dimensional matrix method for differential equations. The temporal dependence of the amplitude of the signal appearing on the detection pixel was calculated for different thicknesses of detection pixel layers. The signal time delay, the maximum signal value, the maximum signal reaching time, the signal decay time to the background, and the detector’s count rate were determined. It is shown that the maximum of the signal is many times higher than the background level, does not depend on the area of photon thermalization in the absorber and has a linear dependence on the photon energy. The construction of the detection pixel also provides for terahertz count rates. The signal time delay is less than a femtosecond. Detectors with such characteristics are in demand in various fields of science and may have a wide range of practical applications in future technologies. [ABSTRACT FROM AUTHOR]

In this paper, we present the results of simulating heat propagation processes in the thermoelectric detection pixel after absorbing single photons of UV radiation with energies ranging from 7.1 to 124 eV. The detection pixels, with an operating temperature of 1 K, consist of an absorber (W), a thermoelectric sensor (La0.99Ce0.01B6), a heat sink (W), and a substrate (Al2O3). The heat transfer processes in the detection pixels with different layer thicknesses and surface areas were modeled and simulated using the three-dimensional matrix method for differential equations based on the equation of heat propagation from a limited volume. The temporal dependencies of the temperature at various points in the detection pixels and the average temperature of the layers' surfaces were calculated. The main signal parameters, such as the maximum value, time to the peak value, decay time, full width at half maximum, and signal power, were determined. In addition, the phonon noise, Johnson noise, and the total noise equivalent power of the detection pixels were calculated. The data obtained show how the signal-to-noise ratio (SNR) depends on the energy of the absorbed photon, the geometry of the detection pixel, and the bandwidth of the signal measurement. Moreover, it was observed that the SNR exceeds unity multiple times for the absorption of photons of all considered energies in the detection pixel with a surface area of 1μm2. [ABSTRACT FROM AUTHOR]

Studies of the Abrikosov vortex motion in superconductors based on time-dependent Ginzburg–Landau equations reveal an opportunity to detect the values of the Aharonov–Bohm type curl-less vector potentials without closed-loop electron trajectories encompassing the magnetic flux. [ABSTRACT FROM AUTHOR]